Decrease in the amount of carbon dioxide gas has been suggested as one of the means for preventing global warming, and various measures have been implemented to attain this object. It is thought to be possible to reduce the global emission of carbon dioxide by half by replacing the presently employed automobiles using internal combustion engines with electric automobiles. Thus, taking into account a high power generation efficiency of electric power generation stations, transmission efficiency, and motor efficiency, the electric automobiles have better efficiency than automobiles using internal combustion engines and are, therefore, highly desirable. However, although the so-called hybrid automobiles using an internal combustion engine together with a storage battery have spread, the popularity of electric automobiles have not yet reached the desirable level due to a high cost thereof.
One of the reasons of a high cost of electric automobiles is in a high cost of large high-capacity storage batteries, and the development of methods for manufacturing large high-capacity storage batteries at a low cost and methods for inexpensively supplying large high-capacity storage batteries are desirable. One more problem is how to charge storage batteries for electric automobiles. It takes a long time to charge a storage battery, and various methods therefor such as using nighttime power have been suggested, but none of such charging methods has been established. In other words, a technology relating to electric automobiles has not yet been established and there is still a large space for improvement and modification.
Large high-capacity storage batteries for use in electric automobiles will be used in environment in which vibrations often occur. Therefore, it is necessary to attach fixedly the large high-capacity storage battery to the electric automobile body and attach fixedly and strongly the plus electrode terminal and minus electrode terminal of the large high-capacity storage battery to the connection cord terminals with screws or the like. The resultant problem is that the replacement operation takes a long time.
The related art will be explained below with reference to patent documents.
A technology relating to a removable battery in an electric automobile in which a battery pack of standardized shape and interface is mounted below a floor of the electric automobile, and a battery pack charged in a gasoline stand or the like is used to replace the empty battery pack (see, for example, Patent Document 1). Further, a technology relating to a standard replaceable secondary battery equipped with a power meter that incorporates the power meter and in which the inputted and outputted power amount can be monitored is also known (see, for example, Patent Document 2).
A technology relating to an electrode connection structure of a storage battery for a vehicle that increases the efficiency of storage battery replacement operation is also known (see, for example, Patent Document 3).
Patent Document 1: Japanese Patent Application Laid-open No. 2001-16706.
Patent Document 2: Japanese Patent Application Laid-open No. 2004-303702.
Patent Document 3: Japanese Utility Model No. 2557531.
With the methods described in the aforementioned patent documents, the replacement cannot be performed by simple operations and within a time equal to or less than that required for gas filling with the conventional gasoline engines. In the configuration described in Patent Document 1, a concave electrode joining portion provided at the vehicle body is connected to a convex electrode of a battery pack. The resultant drawback is that reliability can become a problem under severe conditions of use, such as vibrations. With the technology described in Patent Document 2, it is not clear how the replaceable secondary battery is attached to an electric automobile or the like and some aspects of practical use are unclear. The configuration described in Patent Document 3 is provided with rail-shaped electrode connection portions corresponding to a positive electrode and a negative electrode of a storage battery, and the problem is that the replacement operation is not easy to perform.